1. Field of the Invention
The invention relates to devices for preventing erosion of earthen levees between adjoining fields for growing rice or similar agricultural crops during the flooding of the fields. In particular the present invention relates to coated, woven thermoplastic rice levee gates or sheets having a sleeve into which a wooden plank may be inserted to anchor the levee gate to the earth beneath the gate.
2. Description of the Related Art
As is known in the art, rice is commonly grown in fields which must be periodically flooded with water, and levees made of earth are built around the fields to contain and channel the water in the fields. When it is desired to remove water from a field or to flow water from one field to another, or to evenly distribute water in a single field, commonly a hole or U-shaped channel is made in a levee by removing a portion of a levee to permit water to flow therethrough.
As water flows through the hole in the levee, erosion occurs and an undesired portion of the levee can be eroded by water flowing through the levee if erosion of the levee is not prevented or controlled. To prevent such erosion, devices referred to in the art as "levee gates" are employed.
Levee gates of the prior art are rectangular sheets of coated, woven polyethylene. The coated, woven polyethylene sheets have a hem sewn therein parallel to one edge of the rectangular sheet. The hem is sewn sufficiently far from one edge of the sheet to form a sleeve for receipt of an anchor such as a common elongated wooden plank having an approximate 2" by 4" rectangular cross section to be inserted therein. The wooden plank functions as an anchor to hold the sheet in place and prevent water flowing over the sheet from washing the sheet away. A metal rod or other elongated member may be used to replace the wooden plank if desired.
After a hole is made in a levee containing water on one side thereof, the levee gate described above is placed on the bottom of the hole to prevent erosion and enlargement of the hole. The sleeve of the levee gate containing the anchor is placed on the upstream side of the levee parallel to the levee to prevent the levee gate from being washed away by the water flowing through the hole or channel in the levee. The levee gate may also extend up the sides of the U-shaped hole or channel in the levee if desired to prevent erosion of the side of the U-shaped hole or channel in the levee.
U.S. Pat. No. 4,696,598 discloses an erecting/lying-down dam or sluice gate made of flexible sheet. The dam has a flexible cover attached to a bottom sheet by fittings with corrugations formed between the fittings so that upon deflation the cover conforms to the surface of the corrugations, minimizing any floating cover portion. The corrugations may be formed as pipelike members, as molded portions integral with the bottom sheet or as part of the concrete foundation. Preferably the length between the fittings measured along the corrugation surface is at least 1.1 times the linear length therebetween. The corrugations are also preferably recessed to extend no higher than the bottom of the riverbed.
U.S. Pat. No. 4,541,569 discloses a drip irrigation conduit and method of making the same which is an irrigation conduit comprising an extruded tube having a peripheral wall and at least one elongated passage, and an elongated supply tube having an elongated supply passage. The supply tube is formed of sheet material joined together along longitudinally extending portions to form a seam. A region of the sheet material extends at least part way around the perimeter of the extruded tube, and the extruded tube is retained on such region of the sheet material. Transfer ports extend between the passages of the two tubes and discharge ports extend from the passage of the extruded tube to the exterior of the irrigation conduit.
U.S. Pat. No. 4,231,832 discloses a process of manufacturing laminated web in which the gas and light barrier properties of a web of thermoplastic bags designed for aseptic packaging are improved by laminating a material of high gas and light imperiousness, such as metal foil, to the thermoplastic bag material during a blown film extrusion process. In one embodiment a pair of foil laminates are applied to opposite sides of the inflated length of a blown tube between the extruder and a first pair of nip rolls, with the laminates being pressed into opposite sides of the inflated tube by rollers which flatten the tube at their points of contact to provide flat surfaces for the laminates being applied to the tube. The resulting laminated web has a pair of aligned, uncovered strips running the length of the web along which a slit-seal is made to provide a pair of webs each having a layer of foil or other material laminated to all but one longitudinal edge thereof. In another embodiment a single sheet of foil is applied to a tube of film using, for example, a conventional tube former, with the foil wrapping less than the full circumference of the tube to provide a single web having an uncovered section running longitudinally thereof.
U.S. Pat. No. 4,021,283 discloses a method of making aseptic packaging which are manufactured through a process which includes making an aseptic web of bags by first blow-extruding a continuous, closed thermoplastic tube using a non-contaminating gas, dividing the tube by means of partial, transverse heat seals into a series of interconnected bags intercommunicating with each other in a closed system by means of a continuous channel running across their open mouths an then, while maintaining the closed, and hence, sterile condition of the web of bags, filling the bags with a sterile product and sealing the bags, to produce sealed, aseptic packages.
U.S. Pat. No. 3,855,800 discloses inflatable barriers for watercourses, for example a river, and of the kind including at least one inflatable enclosure secured to an element anchored directly or indirectly in such watercourse and constructed in such a fashion as to prevent erosion. In order to enable the barriers to be easily removed from the watercourse, for example to be used in another location, the invention provides devices for anchoring the enclosure in relation to the watercourse bed, and this device incorporates an anchoring strip of supple material such as rubber that is securable to the bed, and this strip has a free extremity or edge provided with one or more devices for removably connecting the barrier to the strip. The anchoring strip may be secured to a rigid member arranged to be laid down in the soil of the bed of the watercourse and this rigid member may take the form of a block of masonry. Alternatively, the anchoring strip may be embedded in the soil of the bed of the watercourse and this rigid member may take the form of a block of masonry. Alternatively, the anchoring strip may be embedded in the soil of the watercourse by digging out a transverse trench using the removed aggregates to form a temporary dam, laying the anchoring strip in the trench preferably at an angle of 45.degree. to the plane of the bed, and then filling up the trench with the aggregates previously dug out, thus to secure the strip in relation to the soil of the bed.
U.S. Pat. No. 3,130,647 discloses a duplex packaging material including a loosebonded multiple-wall bag, in which the multiple wall includes inner and outer layers of material, and a method of making the same, the method including supplying a first web of bag wall material having properties of resilience and heat-sealability, supplying a second web of bag wall material having a property of relative non-resilience in comparison to the first web of bag wall material, bringing together the first and second webs to superimpose one upon the other, forming a loose-bonded multiple-wall sheet material by effecting a heat seal between the webs over spaced areas which are very limited in relation to the total contacting area of the webs, and forming a multiple-wall, loose-bonded bag from such sheet material by folding a section of the sheet material, securing together longitudinal marginal edge portions of the sheet material and securing together marginal edge portions of the sheet material at least one end of the portion of sheet material, whereby the multiple webs forming the walls of the bag are secured together at limited areas in relation to the total area of the walls.